Means for extracting water from webs of pulp or paper



S OF PULP OR PAPER May 5,- 1936. w. P. EVANS MEANS FOR EXTRACTING WATERFROM WEB Filed June 26, 1934 2 Sheets-Sheet 1 v INVENTOQ'. wuunnPnRsoNnaE Evans HTTORNE W. P. EVANS May 5, 1936.

MEANS FOR EXTRACTING WATER FROM WEBS OF PULP OR PAPER 2 Sheets-Sheet 2Filed June 26, 1954 1? e-l n z I 2,

INVENTQR'. WILLIAM PnnsoNnG: Evans Patented May 5, 1936 MEANS FOR.EXTRACTING WATER. mom WEBS F PULP on PAPER William Parsonage Evans,Swinton, England Application June 26, 1934, Serial No. 732,426 In GreatBritain June 26, 1933 6 Claims. (01. 9252) tracting purposes, use-ismade of a substantially closed suction box structure approximately thewidth of the web and this has spaced lateral apertures and thereco-operates therewith one These improvements are concerned withpaper-making machines, or machines for drying paper, fabrics, or itmight be other materials, but they relate primarily to an improvedmethod of and means for extracting water from the paper web carried uponthe wire in paper-making machines, and whereby I am enabled to obtain abetter drying effect in a simple manner and with less wear and tear uponthe wire and other parts.

It is known to support the wire" in paper making machines upon endlesslaterally corrugated belts and to extract the water by side suctiondevices across the mouths of which the edges of the endless laterallycorrugated belts travel. It is also known to use a laterally corrugatedendless belt to support the wire, and to close the corrugations at theextremities by endless moving side bands, the laterally corrugatedendless belt co-operating with an open topped suction box or boxes inwhich a further endless band operates, there being a series of holes inthe laterally corrugated endless belt leading into the suction box orboxes. In such schemes, as the latter, where holes in the laterallycorrugated belt led to the suction box, considerable disadvantagesfollowed, in so much, that a liquid seal was requisite to the opentopped suction box, a number of endless bands were required, and theatmospheric pressure upon the endless laterally corrugated belt wasconsiderable and extended over the entire area passing over the opentopped suction box or boxes, and which was necessarily a veryappreciable area.

An open-topped suction box the full width of the endless belt issubjected to considerable atmospheric pressure over the functioningarea, whilst with smaller open-topped suction boxes 0 the drainage holesin the corrugated endless belt are local in effect to the size ofsuction box and can only be effective over a limited area. Likewise thesmaller open topped suction boxes do not afford adequate support to thetravelling corrugated endless belt.

My invention has to do with an improved meth- 0d and means which mark aconsiderable advance in the state of the art, in so much that I followan improved method and means which overcome the difiiculties hithertoencountered, in trying to effectively drain water from a paper web orthe like carried on a wire supported by an endless belt which is adaptedto be drained.

According to myimproved method of extract- 5 ing water from the paperweb supported on the wire in paper machines, and for like waterexendless belt having lateral channels, belt drainage holes, and solidselvedges, and the improved method is distinguished by this, that, saidbelt and what it supports is only subjected to atmospheric pressureimmediately over those nar row areas where the belt drainage holes passover the apertures in the substantially closed surface of the suctionbox structure.

of the suction box structu Further the top re, being a substantiallyfiat and closed surface, it affords admirable support to the under faceof the one endless belt,

and d'niiculties of sealing of structure are overcome.

belt to the suctionbox Further, the substantially flat belt supportingface of the substantially closed-in suction box is perforated, or itmight be ribbed, to permit air to pass over areas between belt andsuction box structure, and the suction box structure may be fashioned asto its upper surface to assist the getting rid of silt.

Also the substantially closed suction box structure enables me toconduct the paper web, wire,

and endless revolvable belt in substantially a uniform plane and toresist any tendency to sag into the known open-topped suction box overan appreciable area, which is an obvious drawback entailing considerablepower to effect driving and resulting in much wear and tear.

The means which enable me to operate according to the improved method,include a single endless belt with blank or solid selvedges -which closethe lateral channels, and a practically flat suction box structure inonc or more parts and substantially closed save for the lateralapertures, slots, or holes, and which suction box structure affordsadequate support to the said single endless belt which only requires tosubmit to atmospheric pressure over very narrow and well distributedlateral areas.

The improvements are illustrated in the accompanying drawings, wherein:-

Fig. l is a broken end elevation showing a typical example of theimprovements in connection with the wire of a paper making machine.

Fig. 2 shows a plan of Fig. 1 and clearly indicates the one endless beltbroken away, and also one construction of the substantially closed Fig.2.

belt and suction box Fig. 2.

tion on the line 2--2,

Fig. 5 indicates a portion of a modified endless belt with solid, blank,or closed selvedges, and in which the channels, which are there shown inplan, are sinuous.

Figs. 6 and? are views which show that deckle straps adjustably carriedmay be used to limit the eflective width of the one endless supportbelt.

Fig. 8 is a sectional view showing the suction box structure and theendless revolvable channelled belt in several modified forms.

Fig. 9 is a section of a modified revolvable support belt taken on theline 3-4, Fig. 8.

Fig. 10 is a section of a modified revolvable support belt taken on thelinel-l, Fig. 8.

Fig. 11 is a plan of the suction box structure.

The improvements are illustrated by the Figs.

. 1 and 2 as applied in connection with the "wire of a paper makingmachine, which wire is marked a, and this wire in addition to passingover the known sustaining means receives support from a singlerevolvable endless belt such as b. This belt may be made from anysuitable material or materials, as for instance it may be a rubber orrubber-covered belt, but in any case is fashioned with channels such asb which are close-pitched and have a lateral disposition. The channelsmay be straight or sinuous, as indicated by the Fig. 2 and. Fig. 5.These channels b have belt draining holes I) which are widely arrangedlaterally of the belt but extend, in pitched relationship, across thefull width of the belt. The belt has a solid. blank, or closed selvedgeb along each edge, that is, the channels b do not extend the full widthof the belt so that water passing into the channels I) can only drainthrough the aligned and spaced drainage holes D The endles belt b iscarried upon support rollers c, c, which may be free to revolve, or itmay be driven and there may he means for tensioning the endless belt b.Also means for checking unupper stretch of the belt contactingtherewith. I

Said suction x is substantially a closed vessel, save for lateralapertures or slots :1 at pitched or spaced intervals across the. fullwidth of said suction box and which slots d 'coincide with the beltdrainage holes I); or alternatively. I may provides a'series of holes (1(see Figs. 8 and 11) The suction box :1 is exhausted through the pipes d11 which lead into a common pipe (1* upon which the pump or the likeacts, and the suction from the pump thus'serves to produce a suctioneffect upon the several sets of the lateral apertures or slots (1 or theholes (1 As a consequence, water from the wire a enters the channels b,and is well and evenly distributed over the width of the belt, and, asthe belt drain- .age holes b pass overthe lateral slots d or holes d,sothe water is sucked into the substantially closed suction box anddrained out along the pipes d (1 and d. If Figs. 4 and 8 are examined,it will be seen, how the water is drawn from the channels I) in theendless travelling belt b. It will be'also be seen that suction is onlyexercised upon the well and proportionately distributed areasrepresented by the spaced lateral slots 11 or holes 11, and consequentlythe wire and drive the belt. Further with my proportionately distributedlinable drainage holes b moving over the narrow and correspondinglyspaced lateral apertures, slots, or holes,in the otherwise closedsuction box structure there results a'better distributed drainage effectwith lessened liability for local water accumulation to occur.

In'order to prevent trapping of air or to facilitate the passage of airbetween the endless belt b and substantially closed suction box d, aseries of holes 1 are provided through the upper wall of said suctionbox 11 over which the one endless belt travels. Also, to get rid ofsilt, or the like, below the said endless belt b I may provide'otherapertures e which serve to scrape away such silt and permit same totravel" through and to fall clear of the suction box structure d (seeFigs. 2 and 3).

' The solid, blank. or closed selvedges b define the limits of thechannels b, and the belt drainage holes b come in succession intoregister with the lateral slots d or holes.d ,as the belt I) and wire atravel over the top of the substantially closed suction box d, and soone belt and a supporting suction box structure (closed save where thespaced ranks of belt drainage holes I; register) sumces. for the servicerequired.

The Figs. 8, 9 and 10 suggest slight variations in the structure of thebelt b. According to the Fig. 9 and left-hand portion of Fig. 8 on theline 3-3, the upper face of the belt has a covering 7) of pervious oropen cotton felt or wire gauze, or

both, in addition to the grooves b and belt drainage outlet holes b thebelt necessarily having solid selvedges b In Fig. 10 and the right-handhalf of Fig. 8 on the line 44, the belt has a complete layer.orthickness of perviou's or open cotton felt or the like b the edge stripsor lengths b of which are treated with rubber. and firmly adhered to theselvedges of the belt I). In both these examples the grooves b laterallyof the endless belt b have drainage holes b An important feature of mymethod is that the suction box is in effect a continuous closedstructure over which the one belt passes and which belt is onlysubjected to atmospheric pressure over well distributed comparativelyvery narrow lateral areas, and that with the air relief.

holes f and silt removal apertures e in the u per wall of the suctionbox there is no tendency to set up any vacuum effect between the insideface -of the belt and the support face of the suction aosasoe iect mayvary as between the several substantially closed suction boxes.

I claim:

it Means for carrying out the improved method of extracting water frompaper webs, comprising an endless flexible revolvable belt, laterallyextending channels therein having drainage holes and closed selvedges,all inherent in said belt, said belt being adapted to support the wireand web, a suction bonwherewith the belt cooperates and having laterallyspaced apertures in its upper surface but being: otherwise closed, meansto admit air between said belt and said suction box structure, andrevolvable means to support the belt, ml whereby the disadvantages ofunbalanced atmospheric pressure is overcome and the suction effect onthe belt and what it supports only occurs where the belt passes over thelateral tures in the suction box for the purposes cans for carrying outthe improved method 7 cting water from paper webs, comprising an entreesflexible revolvable belt structure with laterally extending channelstherein having" drainage holes, said belt having solid selvedges supportthe wire and web, and a type, a suction cor: having alternate channelsand ribs on its upper face, said channels having free counication withthe atmosphere and the ribs between the channels having suction portsleading from their upper edges to the intericr"oi the box, and anendless belt for supportingt'hewire belt of the machine having an upperrun resting on said ribs, said endless belt having upstanding flanges atits edges, and provided with closely spaced, channels extel'ldingbetween said flanges, said channels having suction ports in theirbottoms passing successively over the sucstructure and the top oi saidotherwise closed to said belt, drains holes from the channels in saidendless revolvable belt, said'drainage holes adapted to progressivelycoincide with the spaced lateral apertures in the support face of saidsubstantially closed suction box, means to permit free access of airbetween the inner face of the upper stretch of endless revolvable beltand the substantially closed top of the suction box, means to assistremoval of silt between said endless revolvable belt and thesubstantially closed top of the suction box, means for supporting andpermitting rotation of said endless revolvable belt and means fordraining said substantially closed suction box.

5. Means for efiecting extraction or drainage of water from a travellingweb of paper or other .material supported upon a wire, or otherwise,

and consisting of an endless revoivable belt with lateral channels insaid belt, closed selvedges to said belt, drainage holes from" thechannels in said belt, said drainage holes adapted to coincide withdistributed lateral apertures in the support face of a substantiallyclosed suction box, means to permit access of air between the lower faceoi the endless revolvable belt and the substantially closed top of thesuction box, means to assist removal of silt, means to support and permit rotation of said endless revolvable belt,, means to supply water tothe edgesoi said belt, and drainage provision to permit suction drainageof said substantially closed suction box.

6. Means for effecting extraction or drainage of water from a travellingweb of paper or other material supported upon a "wire, or otherwise,comprising a substantially closed suction box structure with supportface and lateral apertures in spaced relationship in said support face,a single endless revolvable belt, lateral channels in said belt, closedselvedges closing said channels at the ends, drainage holes in spacedrelationship from the channels in said belt adapted to coincide with thelateral apertures in spaced relationship in the support face of thesubstantially closed suction box structure, outlet holes to perunitaccess of air between the inner face of said endless revolvable belt andtop of said substantially closed suction box structure, means to asslotremoval of silt, rollers to support and permit rotation of said endlessbelt, means to supply water to the edges of said endless belt, and suc--tion pipe provision to said substantially closed suction box.

- l PARSONAGE EVANS.

